void* child ( void* argV )
{
long myid = (long)argV;
// assert(myid >= 2 && myid <= 5);
/* First, we all wait to get to this point. */
gomp_barrier_wait( &bar );
/* Now, thread #4 writes to 'unprotected' and so becomes its
owner. */
if (myid == 4) {
unprotected = 99;
}
/* Now we all wait again. */
gomp_barrier_wait( &bar );
/* This time, thread #3 writes to 'unprotected'. If all goes well,
Thrcheck sees the dependency through the barrier back to thread
#4 before it, and so thread #3 becomes the exclusive owner of
'unprotected'. */
if (myid == 3) {
unprotected = 88;
}
/* And just to be on the safe side ... */
gomp_barrier_wait( &bar );
return NULL;
}
void
gomp_team_end (void)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
gomp_barrier_wait (&team->barrier);
thr->ts = team->prev_ts;
free_team (team);
}
void
GOMP_single_copy_end (void *data)
{
struct gomp_thread *thr = gomp_thread ();
struct gomp_team *team = thr->ts.team;
if (team != NULL)
{
thr->ts.work_share->copyprivate = data;
gomp_barrier_wait (&team->barrier);
}
gomp_work_share_end_nowait ();
}
void *
GOMP_single_copy_start (void)
{
struct gomp_thread *thr = gomp_thread ();
bool first;
void *ret;
first = gomp_work_share_start (false);
gomp_mutex_unlock (&thr->ts.work_share->lock);
if (first)
ret = NULL;
else
{
gomp_barrier_wait (&thr->ts.team->barrier);
ret = thr->ts.work_share->copyprivate;
gomp_work_share_end_nowait ();
}
return ret;
}
static void *
gomp_thread_start (void *xdata)
{
struct gomp_thread_start_data *data = xdata;
struct gomp_thread *thr;
struct gomp_thread_pool *pool;
void (*local_fn) (void *);
void *local_data;
#if defined HAVE_TLS || defined USE_EMUTLS
thr = &gomp_tls_data;
#else
struct gomp_thread local_thr;
thr = &local_thr;
pthread_setspecific (gomp_tls_key, thr);
#endif
gomp_sem_init (&thr->release, 0);
/* Extract what we need from data. */
local_fn = data->fn;
local_data = data->fn_data;
thr->thread_pool = data->thread_pool;
thr->ts = data->ts;
thr->task = data->task;
thr->place = data->place;
thr->ts.team->ordered_release[thr->ts.team_id] = &thr->release;
/* Make thread pool local. */
pool = thr->thread_pool;
if (data->nested)
{
struct gomp_team *team = thr->ts.team;
struct gomp_task *task = thr->task;
gomp_barrier_wait (&team->barrier);
local_fn (local_data);
gomp_team_barrier_wait_final (&team->barrier);
gomp_finish_task (task);
gomp_barrier_wait_last (&team->barrier);
}
else
{
pool->threads[thr->ts.team_id] = thr;
gomp_simple_barrier_wait (&pool->threads_dock);
do
{
struct gomp_team *team = thr->ts.team;
struct gomp_task *task = thr->task;
local_fn (local_data);
gomp_team_barrier_wait_final (&team->barrier);
gomp_finish_task (task);
gomp_simple_barrier_wait (&pool->threads_dock);
local_fn = thr->fn;
local_data = thr->data;
thr->fn = NULL;
}
while (local_fn);
}
gomp_sem_destroy (&thr->release);
thr->thread_pool = NULL;
thr->task = NULL;
return NULL;
}
static void *
gomp_thread_start (void *xdata)
{
struct gomp_thread_start_data *data = xdata;
struct gomp_thread *thr;
void (*local_fn) (void *);
void *local_data;
#ifdef HAVE_TLS
thr = &gomp_tls_data;
#else
struct gomp_thread local_thr;
thr = &local_thr;
pthread_setspecific (gomp_tls_key, thr);
#endif
gomp_sem_init (&thr->release, 0);
/* Extract what we need from data. */
local_fn = data->fn;
local_data = data->fn_data;
thr->ts = data->ts;
thr->ts.team->ordered_release[thr->ts.team_id] = &thr->release;
if (data->nested)
{
gomp_barrier_wait (&thr->ts.team->barrier);
local_fn (local_data);
gomp_barrier_wait (&thr->ts.team->barrier);
}
else
{
gomp_threads[thr->ts.team_id] = thr;
gomp_barrier_wait (&gomp_threads_dock);
do
{
struct gomp_team *team;
local_fn (local_data);
/* Clear out the team and function data. This is a debugging
signal that we're in fact back in the dock. */
team = thr->ts.team;
thr->fn = NULL;
thr->data = NULL;
thr->ts.team = NULL;
thr->ts.work_share = NULL;
thr->ts.team_id = 0;
thr->ts.work_share_generation = 0;
thr->ts.static_trip = 0;
gomp_barrier_wait (&team->barrier);
gomp_barrier_wait (&gomp_threads_dock);
local_fn = thr->fn;
local_data = thr->data;
}
while (local_fn);
}
return NULL;
}
void
gomp_team_start (void (*fn) (void *), void *data, unsigned nthreads,
struct gomp_work_share *work_share)
{
struct gomp_thread_start_data *start_data;
struct gomp_thread *thr, *nthr;
struct gomp_team *team;
bool nested;
unsigned i, n, old_threads_used = 0;
pthread_attr_t thread_attr, *attr;
thr = gomp_thread ();
nested = thr->ts.team != NULL;
team = new_team (nthreads, work_share);
/* Always save the previous state, even if this isn't a nested team.
In particular, we should save any work share state from an outer
orphaned work share construct. */
team->prev_ts = thr->ts;
thr->ts.team = team;
thr->ts.work_share = work_share;
thr->ts.team_id = 0;
thr->ts.work_share_generation = 0;
thr->ts.static_trip = 0;
if (nthreads == 1)
return;
i = 1;
/* We only allow the reuse of idle threads for non-nested PARALLEL
regions. This appears to be implied by the semantics of
threadprivate variables, but perhaps that's reading too much into
things. Certainly it does prevent any locking problems, since
only the initial program thread will modify gomp_threads. */
if (!nested)
{
old_threads_used = gomp_threads_used;
if (nthreads <= old_threads_used)
n = nthreads;
else if (old_threads_used == 0)
{
n = 0;
gomp_barrier_init (&gomp_threads_dock, nthreads);
}
else
{
n = old_threads_used;
/* Increase the barrier threshold to make sure all new
threads arrive before the team is released. */
gomp_barrier_reinit (&gomp_threads_dock, nthreads);
}
/* Not true yet, but soon will be. We're going to release all
threads from the dock, and those that aren't part of the
team will exit. */
gomp_threads_used = nthreads;
/* Release existing idle threads. */
for (; i < n; ++i)
{
nthr = gomp_threads[i];
nthr->ts.team = team;
nthr->ts.work_share = work_share;
nthr->ts.team_id = i;
nthr->ts.work_share_generation = 0;
nthr->ts.static_trip = 0;
nthr->fn = fn;
nthr->data = data;
team->ordered_release[i] = &nthr->release;
}
if (i == nthreads)
goto do_release;
/* If necessary, expand the size of the gomp_threads array. It is
expected that changes in the number of threads is rare, thus we
make no effort to expand gomp_threads_size geometrically. */
if (nthreads >= gomp_threads_size)
{
gomp_threads_size = nthreads + 1;
gomp_threads
= gomp_realloc (gomp_threads,
gomp_threads_size
* sizeof (struct gomp_thread_data *));
}
}
attr = &gomp_thread_attr;
if (gomp_cpu_affinity != NULL)
{
size_t stacksize;
pthread_attr_init (&thread_attr);
pthread_attr_setdetachstate (&thread_attr, PTHREAD_CREATE_DETACHED);
if (! pthread_attr_getstacksize (&gomp_thread_attr, &stacksize))
pthread_attr_setstacksize (&thread_attr, stacksize);
attr = &thread_attr;
}
start_data = gomp_alloca (sizeof (struct gomp_thread_start_data)
* (nthreads-i));
/* Launch new threads. */
for (; i < nthreads; ++i, ++start_data)
{
pthread_t pt;
int err;
start_data->ts.team = team;
start_data->ts.work_share = work_share;
start_data->ts.team_id = i;
start_data->ts.work_share_generation = 0;
start_data->ts.static_trip = 0;
start_data->fn = fn;
start_data->fn_data = data;
start_data->nested = nested;
if (gomp_cpu_affinity != NULL)
gomp_init_thread_affinity (attr);
err = pthread_create (&pt, attr, gomp_thread_start, start_data);
if (err != 0)
gomp_fatal ("Thread creation failed: %s", strerror (err));
}
if (gomp_cpu_affinity != NULL)
pthread_attr_destroy (&thread_attr);
do_release:
gomp_barrier_wait (nested ? &team->barrier : &gomp_threads_dock);
/* Decrease the barrier threshold to match the number of threads
that should arrive back at the end of this team. The extra
threads should be exiting. Note that we arrange for this test
to never be true for nested teams. */
if (nthreads < old_threads_used)
gomp_barrier_reinit (&gomp_threads_dock, nthreads);
}
